In the prior art, methods and apparatuses are known, with which elongated and web-shaped products are continuously produced and subsequently drawn-off directly from the production machine or from a supply roller, in order to supply them to a further processing or treatment process.
Such a method and such an apparatus is shown, for example by U.S. Pat. No. 2,990,091. This relates to the impregnating of fibers for the production of an elongated fiber reinforced plastic material. The fibers are drawn-off under constant speed from supply rollers and are thereby held under tension. In the tensioned condition, the fibers run through further processing stations. An apparatus with two clamp carriers with clamps for the plastic material to be drawn-off serves for the drawing-off and maintaining of the tension. Guide bolts for the clamp carriers are present in the apparatus frame, on which guide bolts the clamp carriers are guided shiftably in the drawing-off direction. Furthermore a cam disc mechanism is present, by which the clamp carriers are drivable moving back and forth in a travel or shifting range. The clamp carriers are not drivable independently of one another. The travel or shifting displacement is not adjustable and also cannot be very long due to the construction. An adaptation to changed product characteristics or to changed method sequences is thus only possible with difficulty. The guide bolts are tightly clamped into the apparatus frame only at their ends, so that under high tension forces and long travel or shifting displacements it is possible for the guide bolts to bend-through or buckle.
U.S. Pat. No. 3,556,888 describes a similar method as U.S. Pat. No. 2,990,091. In that regard, the drawing-off is served by an apparatus in which several hydraulically driven clamp segments are arranged distributed over the width of the product. The clamp carriers are guided and driven at the bottom side with respect to the apparatus frame. The feed advance in the drawing-off direction is served by a continuously running drive chain, onto which the clamp carriers are coupled-on or uncoupled via a pawl. The force application point of the drive chain and the guide track of the clamp carriers in the apparatus frame have a large spacing distance from the plane in which the tension is developed in the product to be drawn-off. Thereby, with high drawing-off tensions, there exists the danger of deformations and/or over-stressing. A high precision of the alternating motion of the two clamp carriers is hardly achievable.
U.S. Pat. No. 3,819,073 discloses an apparatus for drawing-off pipes or cables from a production machine. The drive of the clamp carriers is achieved via a common drive spindle that is driven by a single motor. The force application point of the drive spindle on the clamp carriers is located below the plane in which the tension is applied to the product to be drawn-off. For the alternating feed advance and return transport of the clamp carriers, these are connected with the drive spindle in a varying manner through a transmission with auxiliary motor. Parallel to the drive spindle, a further spindle is provided, on which several mechanical contact stops are mounted, which serve for operating end switches for the traversing or displacing motions of the clamp carriers.
U.S. Pat. No. 4,478,360 discloses a drawing-off device for band-like material with two clamp carriers that are arranged on both longitudinal sides of the band-like material. The associated clamps alternately grasp the edge or rim of the band-like material respectively from one of the two longitudinal sides. Such an asymmetrical arrangement is not suitable for a precise drawing-off with high tensions.